Class Notes (838,991)
Canada (511,156)
NESC 2470 (13)

Lecture 4, Nov 25th, 2011.docx

4 Pages
Unlock Document

NESC 2470

Lecture 4, Nov 25th, 2011 December-11-11 3:16 PM Homeostasis  The maintenance of the body's internal environment within a narrow physiological range  Controlled by the hypothalamus o Temperature o Blood composition Hypothalamus  Below thalamus  Optic chiasm and pituitary gland located right below it  Along the walls of the third ventricle  Three functional zones o Lateral  Extensive connections in the brain stem & telencephalon o Medial  Extensive connections in the brain stem & telencephalon o Periventricular  Receives much of its input from the other two zones  Cells of this region lie right next to the wall of the third ventricle  Mix of neurons with different functions reside here  One group called superchiasmatic nucleus (SCN)  Lies just above optic chiasm  Receive direct retinal innervation  Synchronize circadian rhythms with light-dark cycle  Other cells control the ANS  Neurosecretory neurons  Extend axons down toward stalk of pituitary gland Pituitary gland  Has 2 lobes o Posterior  Magnocellular neurosecretory cells  Extend around optic chiasm, down stalk, and reside in posterior lobe  Neurons release chemical substances directly into the capillaries of lobe  Called neurohormones  2 types released  Oxytocin  Peptide, 9 amino acid chain  Released during final stages of childbirth  Causes contractions And lactation   Vasopressin  Regulates blood volume and salt concentration  Acts directly on kidneys  Controls how much urine is produced  Kidneys can also communicate with Posterior pituitary gland  Secrete renin into blood  Converts angiotensinogen into angiotensin I  Then breaks down into angiotensin II  Has direct effects on blood vessels and kidney, increase blood pressure  Also detected by subfornical organ  Gives us the urge to drink more o Anterior  Secrete a wide range of hormones  Controlled by parvocellular neurosecretory cells of the periventricular area  Don't extend axons into anterior pituitary  Communicate with via blood stream  Secrete hypophysiotrophic hormones the hypothalamopituitary portal circulation  Bind to specific receptors on the surface of the pituitary cells  Causes pituitary to start or stop secreting hormones Adrenal glands  Located just above the kidneys  2 parts o Adrenal cortex  Shell of gland  Produces cortisol  Mobilizes energy reserves, and supresses immune system o Adrenal medulla  Center of gland Autonomic nervous system (ANS)  Controlled by the hypothalamus  Functions carried out without conscious voluntary control  Sympathetic division o Causes things like your heart rate, and blood pressure to increase o Most active during a crisis  Parasympathetic division o Regulates digestion, growth, immune responses, and energy storage o Bring sympathetic responses back down to normal levels  ANS control o Uses a disynaptic pathway o Preganglionic neurons  Of the sympathetic division Lie within the intermediolateral gray matter of the spinal cord  Axons sent through ventral roots to synapse in the ganglia of the sympathetic
More Less

Related notes for NESC 2470

Log In


Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.